Aneurysm and Dissection Flashcards
Types of aneurysms
True: involves all 3 layers of the vessel wall; saccular or fusiform
False: breaking of the blood wall and formation of a hematoma
Dissection: tear of the intimal layer
Aneurysm pathogenesis
Inadequate or abnormal collagen syntheses; Marfans (cystic medial necrosis), Ehlers-Danlos
Excessive collagen degradation - excess MMPs, low TIMPs; smokers
Aneurysm vessel wall pathogenesis
Intimal thickening - due to atherosclerosis; causes ischemia of inner media
Systemic HTN - narrows vasa vasorum; ischemia of outer media layer
Common causes of aneurysms
Common:
- atherosclerosis - abdominal aortic aneurysm
- HTN - ascending aortic aneurysm
Uncommon causes of aneurysms
Congenital:
- collagen defects
- Berry aneurysm
Infections - myoctic aneurysm; syphilis
Trauma - AV fistula aneurysm
Vasculitis
Most common aortic aneurysm
Abdominal aortic aneurysm - infrarenal aorta
Abdominal aortic aneurysm; pathogenesis and etiology
More common in men and smokers
Most common cause - atherosclerosis
AAA; complications
- Rupture
- Vascular obstruction = of nearby vessels
- Embolism
- Ureter impingement
AAA; management
Surgical repair when it is >5cm; open repair or stent-graft
Thoracic aortic aneurysms; causes
- HTN
- Marfan’s
- Syphilis
Thoracic aortic aneurysms; features
- Tracheal compression
- Esophageal compression
- Recurrent laryngeal nerve compression
- Aortic insufficiency
- Aortic rupture
Aortic dissection; blood location
Between and along laminar planes of media
Aortic dissection; Age and pathogenesis
- HTN = older age
- CT disorders = younger age
Aortic dissection; most common location
Ascending aorta
Rare cause of aortic dissection
Pregnancy
